The invention relates to an output bin for printers, copiers, and other printing devices that output sheet media. More particularly, the invention relates to a bin for capturing and aligning, in a stack, sheet media dispensed from a printing device.
In conventional printing devices such as laser and ink printers, copiers, and facsimile machines, sheets are dispensed one after the other forming stacks in one or more bins or trays located within or near the device. In many instances it is desirable to staple, bind, punch, or cut the stack of sheets collected in a bin. Before such finishing operations can be performed, the edges and corners of the sheets in the stack must be aligned. Referring to FIG. 1, the support surface 10 of some bins 12 is sloped allowing each sheet 14 to slide into place over the top of a sheet 14 previously dispensed into the bin 12 forming a stack 16. Such bins 12 include a floor or stop 18 located near the base of the sloped support surface 10. Gravity, forcing each sheet 14 down the sloped surface 10, aligns the bottom edge of each sheet 14 in the stack 16 against the stop 18. As can be seen in FIG. 2, however, this scheme often fails to align the side edge 20 of the sheets 14 in the stack 16, so additional adjustments are needed before a finishing operation can be performed. More sophisticated bins incorporate mechanical devices for fully aligning the sheets in a stack. However, these mechanical solutions can significantly increase the cost of a printing device. What is needed is a relatively inexpensive bin capable of forming a fully aligned stack of sheets without slowing the output speed of the printing device.
Accordingly, the present invention is directed to an output bin that uses gravity to urge the sheets into alignment along two edges and thereby help form a fully aligned stack. In one embodiment, the bin includes a first panel facing each sheet as the sheet is output from the printing device, the first panel having a top, a bottom and a side; a second panel disposed along the bottom of the first panel, the second panel tipped relative to a leading edge that leads each sheet out of the printing device; and a third panel disposed along the side of the first panel. Each sheet dispensed into the output bin slides over the first panel until a leading edge of the sheet contacts an upper portion of the second tipped panel. The sheet then tips in the direction of the third panel and rests with the leading edge supported by the second panel and a side edge supported by the third panel.